Automatic electric-railway system.



K. E. STUART. AUTOMATIC ELECTRIC RAILWAY SYSTEM.

APPUCATION FILED FEB-2h [916. 1 fi io Patented June12, 1917.

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I8 J T A TTORNE Y UNITED @TATE@ PATENT UFFICEO KENNETH E. STUART, 0F PHILADELPHIA, PENNSYLVANIA.

' AUTOMATIC ELECTRIC-RAILWAY SYSTEM.

Application filed February 21, 1916.

To all whom it may concern Be it known that I, KENNETH E. STUART, a citizen of the United States, residing in the city of Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented new and useful Improvements in Automatic Electric-Railway System, of which the following is a specification.

My invention relates to an electric railway system having motor cars without motormen, and suitable for the transportation of mail, parcels, coal, ore, or any other material.

My invention resides in such an-electric railway system, employing either direct or alternating current for motive power, involving trackways which have junction points, the system being provided with means for preventing collision at such junctionv points, and for automatically restarting any motor car which has been held up to allow another to pass a junction point.

For an illustration of some of the forms my invention may take, reference is to be had to the accompanying drawing, in which:

Figure 1 is a diagram illustrating the system embodying my invention when using direct current for the motive power.

Fig. 2 is a similar diagram of a system employing three phase alternating current as motive power.

Referring to Fig. 1, trailic is assumed to be in the direction of the arrows on the main track comprising the track rails T, T, and the branch track comprising the running rails T T and forming a junction at J, with the main track. Between or otherwise adjacent the main track rails T, T are the armature contact conductor A and the field contact conductor F, the former divided by insulators I and I and the field contact conductor by insulators I and I into a main section immediately preceding the junction J. Similarly with respect to the branch track there extend between or adjacent the track rails T T thereof the armature contact conductor A and field contact conductor F the former divided by insulators I and I and the latter by insulators I and I into a branch section immediately preceding the junction J.

G represents a generator or source of direct current one of whose terminals, preferably the negative, is connected by conductors (t to the track rails T, T and T T of both the main and branch tracks. Its other or Specification of Letters Patent.

Patented June 12, JIQUW.

Serial No. 79,513.

positive terminal is connected by conductor 5 with a switch contact 0 adapted to be brought into electrical connection with the contact (Z through the bridging member 6 attached to the core 7 of the solenoid S. The contact (Z is connected to a lower contact g and through a resistance R to the insulated section of the armature contact conductor A preceding the junction J. Associated with the contact 9 is the contact it connected directly to the track rails T, T. The conductor 5 connects also with the 0011- tact c cooperating with the contact (5 and adapted to be bridged by the bridging contact 6 attached to the core f of the solenoid S The contact al is connected with the lower contact 9 and through the resistance R to the armature contact conductor A forming a section preceding the junction J. The lower contact h connects directly with the track rails T, T which are in electrical communication through conductor a with the track rails T, T of the branch track. The conductor 5 connects also with the two contacts c' and j carried by the rocker arm is pivoted upon the knife edge m. Pivoted to the rocker arm 76 are the cores a and 0 of the solenoids S and S One terminal of each of these solenoids S and S connects with the conductor 6, while the remaining terminal of the solenoid S connects with the section of the field contact conductor F preceding the junction J and the remaining terminal of the solenoid S connects with the section of field contact conductor F of the branch track.

The contact 7' on the rocker arm 74' is adapted to engage the contact 20 which connects through conductor 9 with one terminal of the solenoid S whose other terminal connects directly to the track rails T, T; and contact 1, with which the contact 71 is adapted to engage, is connected through conductor .9 to one terminal of the solenoid S whose other terminal is connected to the track rails T, T.

The center of gravity of the rocker arm is is slightly above the knife edge m upon which it is pivoted, and as the rocker arm moves to one side or the other the air gap or reluctance of the magnetic circuit of the solenoid on the lower side of the rocker arm tends to give that solenoid control of the rocker arm because of its attractive force preponderating over that' exerted by the other solenoid should it simultaneously be energized. The result is that both as to gravity and solenoid attraction the rocker arm l: is in unstable equilibrium and will always assume such position as to close circuit either at contact 7) or contact r, even if both solenoids S and S should be energized simultaneously. This type of switching apparatus may for convenience be termed a tumbler switch. In any intermediate position of the rocker arm is neither contact p nor r is in communication with the conductor Z).

A car is. represented diagrammatically in Fig. 1 by its driving motor. The car wheels travel as usual upon the track rails and make electrical contact therewith. The motor, which is of the shunt wound type, has one terminal of its armature Ma and one terminal of its shunt field winding M) connected to the wheels of the car and through them to the track rails T, T as represented at t. The other terminal of the armature Ma makes contact with the armature contact conductor A by a traveling contact a, and the other terminal of the motor field M7 maintains contact with the field contact conductor F through the traveling contact 4). And other cars are similarly equipped and when traveling on the branch track have their motor electrically connected to the track rails and contact conductors A and F in the manner described.

The operation is as follows:

W hen there is no car upon the main track in the section preceding the unction J, a car may be delivered to the section of the branch track preceding the junction J, as by automatic system described in my co-pending application Serial Number 835,778, filed May 1, 1914, or by any other means. In such event the field of the motor will receive current through conductor 6, solenoid S and the insulated section of field contact conductor F through the motor field to the rails T. This will energize the solenoid S which will then actuate the tumbler switch, moving the arm 7: in counterclockwise direction to bring contact 2' into engagement with contact r and separate contact i from contact 7. The engagement of contact 1 by contact causes current to flow from conductor 7) from these contacts and the conductor .9 through the solenoid S energizing the same, causing it to draw its core 7' upwardly and cause the bridging member 6 to bridge contacts 0 and (Z thereby connecting the armature contact conductor section 1U of the branch track with the conductor Z) through the resistance 0. This will prevent full voltage being impressed upon the motor armature and the car will proceed through the branch track at reduced speed to the unction J, whereupon it will pass on to the main line and forward again under suitable control, as by the system of my aforesaid application. The separation of contact j from contact 7) upon energization of the solenoid S above referred to, breaks the circuit of the solenoid S which is then deenergized and allows its core to drop, thereby bridging contacts 9 and h by the member 6. This then connects the resistance R between the armature contact conductor A of the main track directly with the rails T, T so that should a car move into the section of the main. track from the left toward the right, its field Mf will be energized at full voltage, but the armature Ma will be short circuited through the resistance It, and the motor will therefore act as a generator and so electrodynamically brake the car and bring it to rest, preventing the car on the main track from reaching the junction J, the right of passage over which belongs to the car on the branch track.

Similarly, if both the main track and branch track sections immediately preceding the junctions are unoccupied, a car coming 011 to the main t 'ack section will cause solenoid S to be energized by the field current passed through the field M7, whereupon the arm will be rocked to the position illustrated in Fig. 1, or if previously in such position, will be retained there. This will cause energization of solenoid S to bring the bridging member 6 into the position shown in Fig. l where the main track section armature contact conductor A is connected to the source G through the resistance It which will allow the passage of a car through the section and the junction J to the'main track beyond. And simultaneously it insures the de'energization of the solenoid S causing the bridging contact 6 to be in the position shown in Fig. 1, whereby the armature contact conductor A of the branch section is connected to the running rails T T through the resistance R so that a car entering the branch track section will be braked and brought to rest as previously described. Assuming now that there is a car held up at rest on the branch track section, as soon as the car on the main track section passes the junction J the circuit through solenoid S is broken and solenoid S will gain control of the rocker arm 7c and bring contact 2' into engagement with contact 7" which will energize solenoid S which will then bring the armature contact conductor A of the branch track section into communication with the generator through resistance R thus automatically starting the car on the branch section and delivering it to the main track over the junction J. And while the car on the branch track is so moving thereover toward the junction J the solenoid S is deenergized and the main track section brought to braking condition to brake to rest any car following on the main track; and this following car will be automatically restarted, as described, as soon as the car from the branch track has passed over the junction J to the main track.

If two cars should arrive simultaneously on the main and branch track sections, the one on the section that was last occupied by a car will have the right of way, since under such circumstances the rocker arm will. remain in the position in which it was last set, because notwithstanding energization of both solenoids S and S one will greatly preponderate over the other in its pull upon the rocker arm 70.

If two cars should arrive on the different sections at such an interval apart that both solenoids S and S were energized at the exact instant when the rocker arm is is in mid-position or horizontal, a condition would exist in which, theoretically, both cars would be braked to rest because both solenoids S and S would be deenergized. Such occurrence, however, would be on the side of safety in that both cars would be braked to rest. In practice, however, it would be extremely diificult to have this condition arise, because of the unstable equilibrium of the rocker arm 70 which would take the one position or the other and in so doing allow one car to pass and bring the other to rest. In consequence, protection against collision is complete, and the chance of both cars being stopped is negligible.

In Fig. 2 the motive power is three phase alternating current, the motor upon the car being, for example, an induction motor having a three phase winding on its stator and having a short circuited rotor. The motor is indicated at M and its stator windings are designated respectively 8 s and 8 the outer terminal of the winding 8 communicating with the truck and wheels of the car and thereby maintaining contact at t with the running rails T and T the outer end of the winding 8 maintains contact with conductor A through moving contact m, and the outer end of the winding 8 maintains electrical contact as by traveling contact 1 with contact conductor F.

G represents a generator or source of three phase alternating current, one phase of which is connected to the conductor a which connects with the track rails T, T and T T of the main and branch tracks; the second phase connects to conductor a which connects with the contacts 0 and 0 and the third phase connects with conductor a? which connects with contacts 0 and 6 Besides the bridging contact 6 the core f of solenoid S carries the bridging member e lVhen the solenoid S is energized, as indi cated in Fig. 2, the contacts 0 and (Z are bridged by e, and contacts 0 and (Z are bridged by 6 This closes connection from conductor a to contact conductor F and from conductor a to contact conductor A of the main track section. When solenoid S is deenergized member 6 bridges contacts 7L and g to connect conductor 1) to contact conductor F, and member 6 bridges con tacts 71, and g to connect conductor 6 with contact conductor A of the main track section. Similarly when solenoid S is deenen gized, as illustrated in Fig. 2, the bridging member 6 bridges contacts a and g thereby connecting the conductor 1) with the contact conductor A of the branch track section; and the second bridging member 6" bridges contacts 71 and g to connect conductor .7) with contact conductor F of the branch track section. When solenoid S is energized member 0 bridges contacts 0 and (Z to connect alternating current conductor a with contact conductor A and member (a bridges contacts 0 and CF to connect alternating current conductor a with contact conductor F of the branch track section.

The conductor 72 connects also with one terminal of each of the solenoids S and S and with the contacts 2' and 7' on the rocker arm 76. The contact 72 connects by conductor 1 to the solenoid S whose other terminal is connected to the conductor a of the direct current circuit; and contact 1" connects through conductor 8 with the solenoid S whose other terminal connects to the con ductor a. The remaining terminal of the solenoid S connects with a third contact conductor B extending parallel with the trackway of the main track section; and the remaining terminal of the solenoid S connects with the similar contact conductor B of the branch track section.

As the car whose motor is represented by M enters the main track section the travel.- ing contact C carried by the car engages the contact conductor B and connects the same to the rails T and conductor a, thereby cansing solenoid S to be energized by direct current from the generator G to hold the rocker arm 76 in the position illustrated or to move it to such position, thus causing energization of the solenoid S which makes connection between the generator G and the contact conductors A and F whereby the motor M is energized by alternating current and moves the car from left toward the right past the junction J. The car in this system when on sections other than the main and branch sections may be controlled. by an automatic alternating current system such as described in my prior Patent No.

1,164,671, December 21, 1915. lVhen the contactor k is in the position shown the solenoid S is deenergized and therefore the connection between contact conductors A and F and the alternating current source G is interrupted. And in this case the conductors A and F are in connection with the direct current source G with the result that if a car should pass from left to the right 011 to the branch track section-no alternating current will pass through its stator windings, but direct current will pass therethrough with resultant electro-clynamic braking of the car, as described in the aforesaid Letters Patent, thus bringing the car to rest. As the car on the main track section passes the junction J solenoid will be deenergized and the solenoid S", which was energized by pas age of a car on to the branch track section through traveling contact C of such car and the contact conductor B will now gain control of the rocker arm is and rupture the circuit of the solenoid S and closes the circuit of the solenoid S whereupon the direct current source will be disconnected from contact conductors- A and F and these contact conductors will be connected with the alternating current source G whereupon the car will be automatically started and will pass off the sec tion over the junction J to the main t 'ack.

In other words, the system illustrated in Fig. 2 is similar in principle to that of Fig. 1, the difference residing in the fact that the motive power is alternating current and that the control of the solenoids is effected by direct current.

L is a choke coil or inductance which may be employed to prevent passage of alternating current to the generator G.

What I claim is:

1. In an electric railway system, cars, motors thereon, a plurality of sections, contact conductors for said sections through which energy is transmitted to the car motors, a source of current, and automatic means responsive to the presence of a car in either of said sections for disconnecting one of the contact conductors of another of said sections from said source of current and connecting said other of said sections in a braking circuit, said means responsive when one of said sections is unoccupied to the entry of a car into the other of said sections for reconnecting said contact conductor of said other of said sections to said source of current.

2. In an electric railway system, a car, a motor thereon, a source of current, an armature contact conductor and a field contact conductor extending along the path of travel of said car, said contact conductors divided into insulated sections, and electromagnetic switching mechanism associated with one of said sections of field contact conductor and controlled by current delivered therefrom through a motor on a car arriving in said section for connecting the armature contact conductor of said section with said source of current.

3. In an electric railway system, cars, motors thereon, a plurality of track branches leading to a main track, insulated sections of contact conductors associated with said branches for supplying energy to car motors, and automatic switching mechanism controlling the car motors through said contact conductors, said switching mechanism responsive to the presence of a car in one section to bring the other section into a braking circuit until said car has passed off of said one section to said main track, a source of current, said switching mechanism responsive to the presence of a car in said other section to interrupt said braking circuit and connect said other section with said source of current.

l. In an electric railway system, the combination with a section of main track and a section of branch track having a junction therewith, of cars, motors thereon, main and branch sections of contact conductors for supplying energy to the car motors, and automatic means for completing a braking circuit through the motor of a moving car upon either one of said track sections when the other of said track sections is occupied by a car.

5. In an electric railway system, the combination with a main track and a branch track having a junction therewith, of cars, motors thereon, main and branch sections of contact conductors for supplying energy to the car motors, and automatic electromagnetic switching means controlled by current delivered to contact conductors of said branches for braking a car in one section when the other section is occupied by a second car, a source of current, said switching mechanism after departure of said second car over said junction responding to said first car for establishing connection between said source of current and the contact conductors associated with said first car for restarting the same.

6. In an electric railway system, the combination with branch tracks, of a main track having a junction with said branch tracks, insulated sections of contact conductors associated with said branch tracks, cars, motors thereon receiving energy through said contact conductors, and a tumbler switch controlled by that car first entering either branch section for bringing the other branch section into condition for braking a car.

7. In an electric railway system, the combination with branch tracks, of a main track having a junction with said branch tracks, insulated sections of contact conductors associated with said branch tracks, cars, motors thereon receiving energy through said contact conductors, and a tumbler switch controlled by that car first entering either branch section for bringing the other branch section into condition for braking another car, and a source of current. said tumbler switch after departure over the unction of the car first controlling said tumbler switch responding to the presence of said other car on the other section for reconnecting the motor of said other car to said source of current.

8. In an electric railway system, branch tracks, a main track having a junction with said branch tracks, insulated sections of contact conductors associated with said branch tracks, a tumbler switch comprising a movable contact member and solenoids for moving the same in opposite directions, one of said solenoids energized through a contact conductor of one branch section, the other of said solenoids energized through a contact conductor of the other branch section, cars, motors thereon deriving energy through said contact conductors, a source of current, said tumbler switch in one position causing connection between said source of current and one of said sections and bringging the other section into condition for braking a car, and in the other position alternating the connections of said branch sections, whereby the car on one section causes the braking of a car thereafter entering another section, and after departure of said first car over the junction said second car is automatically placed in communication with said source of current.

9. In an electric railway system, branch tracks, a main track having a junction therewith, cars, motors thereon, armature and field contact conductors divided into insulated sections extending along said branch tracks for delivering energy to the motors of said cars, a tumbler switch comprising a movable contact member and a pair of solenoids, one of said solenoids energized through the field contact conductor of one branch section when a car is present thereon, the other of said solenoids energized through the field contact conductor of the other 7 branch section when a car is present thereon,

an electro-magnetic switch for each branch section having two positions, in one position connecting said section to a source of current and in the other position bringing said section into a braking position, said tumbler switch in its alternate positions causing said electroanagnetic switches to take alternate positions.

10. In an electric railway system, branch tracks, a main track having a junction therewith, cars, motors thereon, contact conductors divided into sections extending along said branch tracks for supplying energy to the car motors, a tumbler switch controlling said sections to alternately connect said sections to a source of current or bring them into braking circuits, said switch responding to the presence of a car in either section, said switch remaining in its last position upon simultaneous entry of cars into said branch sections, whereby the car entering the section last occupied passes thereover and the car on the other section is braked.

11. In an electric railway system, branch tracks, a main track having a junction therewith, cars, motors thereon, contact conductors divided into sections extending along said branch tracks for supplying energy to the on r motors, a tumbler switch controlling said sections to alternately connect said sections to a source of current or bring them into braking circuits, said switch responding to the presence of a car in either section, said switch in transit from its one position to another causing both sections to be brought into braking condition, whereby a car arriving in one of said sections a short time interval after the arrival of a car in another of said sections will cause both cars to be braked until said switch takes one or the other of its positions, whereafter one of said cars will be further braked and the other energized from said source of current and delivered over said junction.

12. In an electric railway system, the combination with a plurality of track sections, insulated sections of contact conductors associated with said track sections, cars, motors thereon receiving energy through said contact conductors, and switching mechanism common to said track sections and controlled in response to the presence of a car 011 either to bring another into condition for braking a car.

13. In an electric railway system, the combination with a plurality oi track sections, insulated sections of contact conductors associated with said track sections, cars, motors thereon receiving energy through said contact conductors, and switching mechanism common to said track sections and controlled in response to the presence of a car on either to bring another into condition for braking a car, said switching mechanism remaining in position to which last operated after passage of the car from the section last controlling the same.

14. In an electric railway system, the combination with a section of main track and a section of branch track having a junction therewith, of cars, motors thereon, main and branch sections of contact conductors for supplying energy to the car motors, and means including an automatically operated switching mechanism controlled through each of said contact conductor sections for bringing a car to rest on one of said track sections when the other of said track sections is occupied by a car.

15. In an electric railway system, the combination with two adjoining track sections, of cars, motors thereon, sections of contact conductors extending along the trackway for supplying energy to the car motors, and means including an automatically operated device under the control of each of said track sections for completing a braking circuit through the motor of a car entering upon either one of said track sections when the other of said track sections is occupied by a car.

16. In an electric railway system, the combination with adjoining track sections, of cars, motors thereon, contact conductors extending along the trackway for supplying energy to the car motors, and means including an automatically operated switching mechanism controlled through one of said contact conductor sections of said track section for bringing a car to rest on one of said track sections when the other of said track sections is occupied by a car, said switching mechanism remaining in the position to which actuated through one of said contact conductors until actuated through the other of said contact conductors.

17. In an electric railway system, the combination with track sections, of cars, motors thereon, contact conductors extending along the trackway for supplying energy to the car motors, and automatic means under control from each of said sections for bringing to rest a car entering upon either of said sections when the other of said sections is occupied by a car or cars and for maintaining said first car at rest until said other of said sections is clear.

18. In an electric railway system, the combination with track sections, of cars, motors thereon, contact conductors extending along the trackway for supplying energy to the car motors, automatic means under control from each of said sections for bringing to rest any car entering upon either of said sections when another of said sections is occupied by a car or cars and for maintaining said first car at rest until said other of said sections is clear, and automatic means for restarting said arrested car.

19. In an electric railway system, branch tracks, a main track having a junction therewith, cars, motors thereon, armature and field contact conductors divided into insulated sections extending along said branch tracks for delivering energy to the motors of said cars, switching mechanism adapted to take two positions and comprising a movable contact member and a pair of solenoids, one of said solenoids energized through the field contact conductor of one branch section when a car is present thereon, the other of said solenoids energized through the field contact conductor of the other branch section when a car is present thereon, an electro-magnetic switch for each branch section having two positions, in one position connecting said section to a source of current and in the other position bringing said section into a braking position, said switching mechanism in its alternate positions causing said electro -magnetic switches to take alternate positions.

20. In an electric railway system, branch tracks, a main track having a junction therewith, cars, motors thereon, contact conductors divided into sections extending along said branch tracks for supplying energy to the car motors, means controlling said sections to alternately connect said sections to a source of current for bringing them into braking circuits, said means responding to the presence of a car on either section, said means in transit from its one position to another causing both sections to be brought into braking condition, whereby a car arriving at one of said sections a short time interval after the arrival of a car in another of said sections will cause both cars to be braked until said switch takes one or the other of its positions, whereafter one of said cars will be further braked and the other energized from said source of current and delivered over said junction.

In testimony whereof I have hereunto affixed my signature this 18 day of February 1916.

- KENNETH E. STUART.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

